OPA4658 Datasheet, PDF (12/15 Pages) Burr-Brown (TI) – Quad Wideband, Low Power Current Feedback OPERATIONAL AMPLIFIER

was used to establish a reference against which the perfor-
mance of the amplifier was measured. Signal averaging was
also used to measure the DG and DP of the test signal in order
to eliminate the generator’s contribution to measured ampli-
fier performance. Typical performance of the OPA4658 is
0.015% differential gain and 0.02° differential phase to both
NTSC and PAL standards.
NOISE FIGURE
The OPA4658’s voltage and current noise spectral densities
are specified in the Typical Performance Curves. For RF
applications, however, Noise Figure (NF) is often the pre-
ferred noise specification since it allows system noise per-
formance to be more easily calculated. The OPA4658’s
Noise Figure vs Source Resistance is shown in Figure 9.
SPICE MODELS
Computer simulation using SPICE is often useful when
analyzing the performance of analog circuits and systems.
This is particularly true for Video and RF amplifier circuits
where parasitic capacitance and inductance can have a major
effect on circuit performance. SPICE models using MicroSim
Corporation’s PSpice are available for the OPA4658. Evalu-
ation PC boards are also available. Contract Burr-Brown
applications departments to receive a SPICE Diskette.
40
30
NF = 10LOG
1+
e_n2 + (InR_s)²
4KTR_S
20
10
0
10
100
1k
10k
Source Resistance (Ω)
100k
FIGURE 9. Noise Figure vs Source Resistance.
DEMONSTRATION BOARD
DEM-OPA465xP
DEM-OPA465xU
PACKAGE
8-Pin DIP
SO-8
PRODUCT
OPA4658P
OPA4658U
OPA4658UB
TYPICAL APPLICATIONS
402Ω
402Ω
Video
Input
1/4
OPA4658
75Ω
75Ω Transmission Line
75Ω
75Ω
V_OUT
FIGURE 10. Low Distortion Video Amplifier.
®
OPA4658
12